Hard metallic materials, hard metallic coatings, methods of processing metallic materials and methods of producing metallic coatings

ABSTRACT

The invention includes a method of producing a hard metallic material by forming a mixture containing at least 55% iron and at least one of B, C, Si and P. The mixture is formed into an alloy and cooled to form a metallic material having a hardness greater than about 9.2 GPa. The invention includes a method of forming a wire by combining a metal strip and a powder. The strip and powder are rolled to form a wire containing at least 55% iron and from 2-7 additional elements including at least one of C, Si and B. The invention also includes a method of forming a hardened surface on a substrate by processing a solid mass to form a powder, applying the powder to a surface to form a layer containing metallic glass, and converting the glass to a crystalline material having a nanocrystalline grain size.

RELATED PATENT DATA

[0001] This application is a continuation-in-part of U.S. applicationSer. No.: 09/709,918 which was filed on Nov. 9, 2000 and which is herebyincorporated by reference.

CONTRACTUAL ORIGIN OF THE INVENTION

[0002] This invention was made with United States Government supportunder contract number DE-AC07-99ID13727, awarded by the United StatesDepartment of Energy. The United States Government has certain rights inthe invention.

TECHNICAL FIELD

[0003] The invention pertains to hard metallic materials and methods offorming hard metallic materials.

BACKGROUND OF THE INVENTION

[0004] Steel is a metallic alloy which can have exceptional strengthcharacteristics, and which is accordingly commonly utilized instructures where strength is required or advantageous. Steel can beutilized, for example, in the skeletal supports of building structures,tools, engine components, and protective shielding of modern armaments.

[0005] The composition of steel varies depending on the application ofthe alloy. For purposes of interpreting this disclosure and the claimsthat follow, “steel” is defined as any iron-based alloy in which noother single element (besides iron) is present in excess of 30 weightpercent, and for which the iron content amounts to at least 55 weightpercent, and carbon is limited to a maximum of 2 weight percent. Inaddition to iron, steel alloys can incorporate, for example, manganese,nickel, chromium, molybdenum, and/or vanadium. Accordingly, steeltypically contains small amounts of phosphorus, carbon, sulfur andsilicon.

[0006] Steel comprises regular arrangements of atoms, with the periodicstacking arrangements forming 3-dimensional lattices which define theinternal structure of the steel. The internal structure (sometimescalled “microstructure”) of conventional steel alloys is always metallicand polycrystalline (consisting of many crystalline grains). Bothcomposition and processing methods are important factors that effect thestructure and properties of a steel material. In conventional steelprocessing, an increase in hardness can be accompanied by acorresponding decrease in toughness. Steel material produced byconventional methods that increase the hardness of the composition canresult in a steel material that is very brittle.

[0007] Steel is typically formed by cooling a molten alloy. Forconventional steel alloys, the rate of cooling will determine whetherthe alloy cools to form an internal structure that predominatelycomprises crystalline grains, or, in rare cases a structure which ispredominately amorphous (a so called metallic glass). Generally, it isfound that if the cooling proceeds slowly (i.e. at a rate less thatabout 10⁴ K/s), large grain sizes occur, while if the cooling proceedsrapidly (i.e. at rate greater than or equal to about 10⁴ K/s)microcrystalline internal grain structures are formed, or, in specificrare cases not found in conventional steel alloy compositions, anamorphous metallic glass is formed. The particular composition of amolten alloy generally determines wether the alloy solidifies to formmicrocrystalline grain structures or an amorphous glass when the alloyis cooled rapidly.

[0008] Both microcrystalline grain internal structures and metallicglass internal structures can have properties which are desirable inparticular applications for steel. In some applications, the amorphouscharacter of metallic glass can provide desired properties. Forinstance, some glasses can have exceptionally high strength andhardness. In other applications, the particular properties ofmicrocrystalline grain structures are preferred. Frequently, if theproperties of a grain structure are preferred, such properties will beimproved by decreasing the grain size. For instance, desired propertiesof microcrystalline grains (i.e., grains having a size on the order of10⁻⁶ meters) can frequently be improved by reducing the grain size tothat of nanocrystalline grains (i.e., grains having a size on the orderof 10⁻⁹ meters). It is generally more problematic, and not generallypossible utilizing conventional approaches, to form grains ofnanocrystalline grain size than it is to form grains of microcrystallinegrain size.

[0009] It is desirable to develop improved methods for formingnanocrystalline grain size steel materials. Further, as it is frequentlydesired to have metallic glass structures, it is desirable to developmethods of forming metallic glasses. Still further, it is desirable todevelop methods of processing steel that can achieve an increasedhardness without a corresponding loss of toughness.

SUMMARY OF THE INVENTION

[0010] In one aspect, the invention encompasses a method of producing ahard metallic material. A mixture of elements containing at least about55% iron by weight, and at least one of B, C, Si and P is formed into analloy and the alloy is cooled at a rate of less than about 5000 K/s toform a metallic material having a hardness of greater than about 9.2GPa. In one aspect the invention encompasses a metallic materialcomprising at least 55% iron and at least one of B, Si, P and C. Thematerial has a total element composition of fewer than eleven elements,excluding impurities, has a melting temperature between about 1100° C.and about 1250° C. and has a hardness of greater than about 9.2 GPa. Inone aspect the invention encompasses a method of forming a wire. A metalstrip having a first composition and a powder having a secondcomposition are rolled/extruded together to combine the firstcomposition and the second composition to form a wire having a thirdcomposition. The third composition contains at least 55% iron, byweight, and from 2-7 additional elements including at least one of C, Siand B.

[0011] In one aspect the invention encompasses a method of forming ahardened surface on a substrate. A solid mass having a first hardness isprocessed to form a powder. The powder is applied to a surface of asubstrate to form a layer having a second hardness. At least some of thelayer contains metallic glass which may be converted to a crystallinematerial having a nanocrystalline grain size. The converting themetallic glass to a crystalline material hardens the layer to a thirdhardness that is greater than the first hardness and greater than thesecond hardness.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0013]FIG. 1 is a block-diagram flow chart view of a method encompassedby the present invention.

[0014]FIG. 2 is a block-diagram flow chart view of a processing methodencompassed by the present invention.

[0015]FIG. 3 is a SEM micrograph of a metallic powder produced bymethods of the present invention.

[0016]FIG. 4 is a fragmentary, diagrammatic, cross-sectional view of ametallic material at a preliminary processing step of a method of thepresent invention.

[0017]FIG. 5 is a view of the FIG. 4 metallic material shown at aprocessing step subsequent to that of FIG. 4.

[0018]FIG. 6 is a fragmentary, diagrammatic, cross-sectional view of ametallic material substrate at a treatment step of a process encompassedby the present invention.

[0019]FIG. 7 shows examples of coatings comprising Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄formed by high velocity oxy-fuel deposition onto 4340 alloy steel, 13-8stainless steel and 7075 aluminum substrates.

[0020]FIG. 8 shows a cross-section indicative of a porosity of aFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ coating from FIG. 7.

[0021]FIG. 9 shows cross-sections demonstrating porosities of coatingscomprising (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ deposited by plasmadeposition (Panel A), high velocity oxy-fuel deposition (Panel B), andWire-Arc deposition (Panel C).

[0022]FIG. 10 illustrates an x-ray diffraction scan of a free surface ofa 330 micron thick, high velocity oxy-fuel deposited coating comprisingFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄.

[0023]FIG. 11 illustrates x-ray diffraction scans of a free surface(Panel A) and a substrate-interface surface (Panel B) of a 1650 micronthick, plasma-sprayed coating comprising Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄.

[0024]FIG. 12 illustrates an x-ray diffraction scan of a free surface ofa 0.25 inch thick coating formed by wire-arc spraying utilizing a wirehaving the composition (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂.

[0025]FIG. 13 illustrates data obtained from differential thermalanalysis of atomized powder (top graph), a high velocity oxy-fuelcoating (middle graph) and a plasma sprayed coating of the compositionFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄. The graph curves show glass to crystallinetransitions of the tested forms of the composition and the meltingtemperature of the composition.

[0026]FIG. 14 illustrates differential scanning calorimetry dataacquired from a 0.25 inch thick coating formed by wire-arc deposition ofcomposition Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄. The graph shows the glass tocrystalline transition of the coating.

[0027]FIG. 15 shows SEM micrographs and corresponding selected areadiffraction patterns of a metallic material produced from a compositioncomprising (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂ by methods of the presentinvention after heat treatment for one hour at 700° C. (Panel A), 750° C(Panel B) or 800° C. (Panel C).

[0028]FIG. 16 shows SEM micrographs and corresponding selected areadiffraction patterns of a metallic material produced from a compositioncomprising (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ by methods of thepresent invention after heat treatment for one hour at 600° C. (PanelA), 700° C. (Panel B) or 800° C. (Panel C)

[0029]FIG. 17 is an SEM micrograph of a coating comprisingFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ formed by methods of the present inventionutilizing HVOF deposition followed by treatment for one hour at 600° C.

[0030]FIG. 18 illustrates measured (Panel A) and Rietveld refined(calculated, Panel B) x-ray diffraction patterns of a high velocityoxy-fuel coating comprising the composition(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ after heat treating the coating for1 hour at 750° C.

[0031]FIG. 19, Panel A shows an example of a strip of steel coated withFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ to a thickness of approximately 200 microns. Thecoating was applied using high-velocity oxy-fuel deposition. Panel B andPanel C show the effects on the coating during bending of the coatedstrip.

[0032]FIG. 20 shows a flat plate of base-metal with an approximately 200micron thick coating of Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ formed by high velocityoxy-fuel deposition. Identically formed plates were used to show a plateas formed (Panel A), a plate after being repeatedly hammered on thecoating side (Panel B) or on the substrate side (Panel C), and a plateafter sever plastic deformation (Panel D).

[0033]FIG. 21 illustrates true-stress/true-strain measurements obtainedfrom metallic ribbons comprising metallic glass of the composition(Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂. The graph curves reflect data obtained at 20°C. at a strain rate of 10⁻³s⁻¹ (Panel A); at 450° C. (Panel B) at strainrates of 10⁻⁴s⁻¹ (closed circles) and 10⁻²s⁻¹ (open circles); at 500° C.(Panel C) at strain rates of 10⁻⁴s⁻¹ (closed circles), 10⁻²s⁻¹ (opencircles) and 10⁻s⁻¹ (triangles); and at 550° C. (Panel D) at strainrates of 10⁻¹s⁻¹ (open circles) and 10⁻²s⁻¹ (closed circles).

[0034]FIG. 22 illustrates true-stress/true-strain measurements obtainedfrom metallic ribbons of the composition (Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂ aftercrystallization. The curve reflects data obtained at 750° C. at a strainrate of 10⁻⁴s⁻¹. Crystallization was achieved by heating the compositionto above the crystallization temperature but lower than the meltingtemperature of the composition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0036] The invention encompasses methodology for forming metallic glasssteel materials and for forming steel materials having nanocrystallinescale composite microstructures, methods of utilizing such steelmaterials, and also encompasses the steel material compositions. Aprocess encompassed by the present invention is described generally withreference to the block diagram of FIG. 1. At an initial step (A) amixture of elements is formed. Such mixture comprises a steelcomposition. An exemplary mixture comprises at least 55% iron, byweight, and can comprise at least one element selected from the groupconsisting of B, C, Si and P. In particular aspects of the presentinvention, the mixture will comprise at least two of B, C and Si. Themixture can comprise B, C and Si, and in particular embodiments themixture can comprise B, C and Si at an atomic ratio of B₁₇C₅Si₁. Inparticular aspects of the present invention, the mixture can contain atleast one transition metal which can be, for example, selected from thegroup consisting of W, Mo, Cr and Mn. In addition, the mixture cancontain one or more of Al and Gd.

[0037] Mixtures of the present invention preferably comprise fewer thaneleven elements, and can more preferably comprise fewer than nineelements. Additionally, the mixtures can comprise as few as twoelements. In particular embodiments, the mixture can consist essentiallyof or can consist of fewer than eleven elements. Further, the mixturecan consist essentially of, or can consist of as few as two elements.Generally, mixtures of the present invention are composed of from fourto eight elements.

[0038] Exemplary mixtures which can be utilized in methodology of thepresent invention are: Fe₆₃Mo₂Si₁, Fe₆₃Cr₈Mo₂, Fe₆₃Mo₂Al₄,(Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂, (Fe_(0.8)Mo_(0.2))₈₃B₁₇, Fe₆₃B₁₇Si₁,Fe₆₃Cr₈Mo₂C₅, Fe₆₃Mo₂C₅, Fe₈₀Mo₂₀, Fe₆₃Cr₈Mo₂B₁₇, Fe₈₃B₁₇, Fe₆₃B₁₇Si₅,Fe₆₃B₁₇C₂, Fe₆₃B₁₇C₃Si₃, (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅,Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈, Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁,Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅, (Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂, Fe₆₃Cr₈Mo₂B₁₇C₅,(Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.

[0039] At step (B) of FIG. 1, the mixture can be formed into an alloy.Alloy formation step (B) can comprise, for example, melting acomposition under an argon atmosphere.

[0040] At step {circle over (c)}) of FIG. 1, the alloy can be cooled toform a hard material comprising a solid mass. Cooling of conventionalsteel alloys to form solid materials typically comprises cooling at arate of at least about 5000 K/s, in order to achieve a hard steel solid.For purposes of the present description, cooling at a rate of at leastabout 5000 K/s can be referred to as rapid cooling. Rapid cooling can beaccomplished by a number of different processes, including, for example,melt-spinning, gas atomization, centrifugal atomization, wateratomization and splat quenching. Alternatively, Step {circle over (c)})of FIG. 1 can comprise fast cooling or alternatively can comprise slowcooling (cooling at a rate of less than or equal to about 5000 K/s) toform a hard solid material. Slow cooling of an alloy can preferablycomprise cooling at a rate of less than about 5000 K/s and can utilizemethods such as arc-melting, casting, sand casting, investment casting,etc. The rate of cooling and the resulting hardness of the hard metallicmaterial can vary depending on the particular composition of the mixtureused to form the alloy. In particular embodiments, a hard metallicmaterial formed by the methods of the present invention can comprise ahardness of greater than about 9.2 GPa. Additionally, contrary toconventional steels compositions that are rapidly cooled to achieve highhardness, particular alloy compositions of the present invention canachieve extreme hardness (greater than about 9.2 GPa) by slow cooling.

[0041] The hard solid material formed in step {circle over (c)}) of FIG.1 can comprise a melting temperature of, for example, between about1100° C. and about 1550° C. The hard solid material formed in step{circle over (c)}) of FIG. 1 is not limited to a specific form and canbe, for example, a cast material including but not limited to an ingotform. The formation of a hard solid material by the processing stepsshown in FIG. 1 can comprise standard metallurgy techniques including,but not limited to, arc-melting, investment casting, sand casting, sprayforming and spray rolling.

[0042] Measured hardness (GPa) for as-cast ingots of selectedcompositions encompassed by the present invention are reported inTable 1. The ingots were cut in half with a diamond saw,metallo-graphically mounted, and tested for hardness, with each reportedhardness value representing an average of ten measurements. As shown inTable 1, the resulting as-cast ingots can comprise a hardness as high as14.9 GPa.

[0043] Although the cooled alloy in solid mass form can comprise a veryhigh hardness, the hardness can be accompanied by very low toughness.Due to the low toughness, ingots formed as described above can be verybrittle and can shatter upon impact, as, for example, when struck with ahammer. However, contrary to an observed decrease in toughness thataccompanies increased hardness in materials produced by conventionalsteel processing, further processing of the solid mass material bymethods of the present invention(discussed below) can produce materialshaving both extreme hardness and increased toughness relative to theingot form. TABLE 1 Hardness of Ingots Ingot Composition Hardness (GPa)Fe₆₃B₁₇C₃Si₃ 10.3 (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂ 10.8 Fe₆₃B₁₇C₃Si₅ 11.1Fe₆₃B₁₇C₂W₂ 11.2 Fe₆₃B₁₇C₈ 11.9 Fe₆₃B₁₇C₅ 12.1(Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁ 12.1 Fe₆₃B₁₇C₅W₅ 12.3 Fe₆₃B₁₇C₅Si₅12.3 (Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁ 12.3(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ 12.3 Fe₆₃Cr₈Mo₂B₁₇C₅ 12.5(Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁ 12.7 Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ 13.2(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁ 13.4 Fe₆₃B₁₇C₅Si₁ 13.7(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁ 14.0(Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁ 14.4(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂ 14.7(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁ 14.9

[0044] Additional and alternative processing of the alloy of FIG. 1 step(B) and the hard solid material of FIG. 1 step {circle over (c)}) isdescribed generally with reference to the block diagram of FIG. 2. Analloy according to methods of the present invention can comprise amolten alloy as shown in FIG. 2 step (D). The molten alloy can besolidified in step (E) by rapid cooling or by slow cooling according tothe methods discussed above. The solidified material can be subjected toa further processing step (F) to form a powder. Alternatively, themolten alloy of step (D) can be directly subjected to powder formationstep (F).

[0045] Processing the solid material step of step (E) into a powder formcan comprise, for example, various conventional grinding or millingsteps or atomization methods such as, for example, gas, water, orcentrifugal atomization to produce a metallic powder. In particularembodiments of the present invention, it can be advantageous to processa solid material to form powder utilizing atomization techniques sincesuch processing can produce large amounts of stable, non-reactivepowders of a desired size range in a single step. Atomization methodscan produce spherical powders which can be especially advantageous sincespherical particles can flow easily allowing improved passage through athermal deposition device (see below). The spherical nature of powderparticles produced from a hard steel ingot of alloy composition is shownin FIG. 3.

[0046] In particular aspects of the present invention, formation ofpowder particles by atomization can form powder particles that compriseat least some amorphous microstructure. Due to the high glass formingabilities of compositions of the present invention, rapid solidificationduring atomization allows direct production of amorphous glassparticles. In particular embodiments it can be desirable to produceamorphous particles and thereby limit or eliminate the need to remeltthe particles during subsequent deposition. Particular compositionsprocessed by methods of the present invention can produce powders whichcomprise up to 100% amorphous structure.

[0047] As shown in FIG. 2, metallic powder from step (F), can be formedfrom molten alloy from step (D) according to methods of the presentinvention without the inclusion of solidification step (E). Such directpowder formation can be achieved by utilizing rapid solidificationmethods such as radiative cooling, convective cooling, or conductivecooling, or alternatively by any of the atomization methods discussedabove with respect to processing of a solid metallic material intopowder form. The advantages discussed above with respect to atomizationof the solid material apply equally to atomization of a molten alloyaccording to methods of the present invention.

[0048] Prior to a surface application step (H) of FIG. 2, the metallicpowder of step F can be further processed by classification (sorting thepowder based on particle size (not shown)). Such classification cancomprise, for example, sequential sieving and air classification steps.Particle sizes for powders produced by methods of the present inventioncan comprise sizes from between about 10 μm to about 450 μm. Particleclassification of the powder can be used to obtain a specific ofparticle size or range of sizes useful for a chosen material depositiontechnique. In particular embodiments, classification can be used toproduce a powder comprising a particle size of from about 10 to about100 microns.

[0049] Still referring to FIG. 2, a powder produced by methods of thepresent invention can optionally be utilized for production of a wire instep (G), which can in turn be used for application to a surface in step(H). Wire formation step (G) of FIG. 2 is discussed in more detail withreference to FIGS. 4 and 5.

[0050] First referring to FIG. 4, wire formation can comprise providinga metal strip 20 that can have a first composition, and providing apowder that can have a second composition. The composition of the metalstrip 20 and the composition of powder 22 can be combined to form adesired wire composition for subsequent deposition or otherapplications. Powder 22 is not limited to a specific powder and cancomprise, for example, a powder produced by methods of the presentinvention discussed above. The composition of metal strip 20 is notlimited to any specific composition and can be chosen to supplement thecomposition of powder 22 to form the desired wire composition

[0051] Metal strip 20 can be combined with powder 22 and furtherprocessed to form wire 24 as shown in FIG. 5. The combining of the metalstrip and the powder can comprise, for example, forming a cored wireutilizing conventional rolling/extrusion techniques wherein the powdermaterial forms a core 28 and the metal strip forms a sheath 26 aroundcore 28. Wire 24 is not limited to a specific diameter and can comprise,for example, a diameter of from about 0.035 inches to about 0.188inches. In particular embodiments, a preferred wire diameter can be{fraction (1/16)} inches.

[0052] A total composition of wire 24 comprising the combinedcompositions of core 28 and sheath 26, can include at least 55% iron byweight. The total composition of wire 24 can preferably comprise fewerthan eleven elements. In particular embodiments, the total compositionof wire 24 can consist essentially of the fewer than 11 elements.Preferably, the total composition of wire 24 can comprise or can consistessentially of from 2-7 elements in addition to the iron. Elements otherthan iron present in the total composition can include at least oneelement selected from the group consisting of C, B, P, and Si. Inparticular embodiments wire 24 can comprise 2, 3 or all of C, B, P, andSi. Wire 24 can, for example, comprise C, Si and B present in the totalcomposition at an atomic ration of B₁₇C₅Si₁. The total composition canfurther contain one or more of W, Mo, Cr, Mn, Al and Gd.

[0053] Exemplary total compositions which can be comprised by wire 24include: Fe₆₃Mo₂Si₁, Fe₆₃Cr₈Mo₂, Fe₆₃Mo₂Al₄, (Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂,(Fe_(0.8)Mo_(0.2))₈₃B₁₇, Fe₆₃B₁₇Si₁, Fe₆₃Cr₈Mo₂C₅, Fe₆₃Mo₂C₅, Fe₈₀Mo₂₀,Fe₆₃Cr₈Mo₂B₁₇, Fe₈₃B₁₇, Fe₆₃B₁₇Si₅, Fe₆₃B₁₇C₂, Fe₆₃B₁₇C₃Si₃,(Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅, Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈,Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁, Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅,(Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂,Fe₆₃Cr₈Mo₂B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si1, (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.

[0054] The powder used for wire formation is not limited to a specificmicrostructure and can comprised from about 0 to about 100% amorphous(metallic glass) structure. Preferably the powder utilized for wireformation will comprise a composition which, when alloyed with themetallic wire sheath, will produce an alloy composition capable ofmetallic glass formation. The final composition of wire produced by thepresent invention can preferably comprise a volume fraction contributedby powder of from about 10% to about 60%.

[0055] The particle size range for powders utilized in wire formationaccording to methods of the present invention is not limited to aspecific value. Since wire formation does not require a specific powdersize, wire formation according to methods of the present invention canutilize any non-classified powders or powder classification includingsizes that are outside the preferred particle size ranges for variouspowder deposition techniques.

[0056] Referring again to FIG. 2, the powder from step (F) or the wirefrom step (G) can be utilized to treat a surface in step (H). Metallicmaterial in powder form or in wire form can be applied to a surface instep (H) to form a layer or coating over the surface. Application of apowder or wire feedstock according to methods of the present inventionis described in more detail with reference to FIG. 6.

[0057] As shown in FIG. 6, a substrate 50 is provided for treatment of asurface 51. Surface 51 can comprise a metal surface such as, forexample, a conventional steel surface, an aluminum surface, a stainlesssteel surface, a tool steel surface or any other metallic surface.Alternatively, surface 51 can comprise a non-metallic material such as,for instance, a ceramic material. Powder or wire, for example powder orwire produced by the methods discussed above, can be used for feedstockfor deposition onto surface 51. Exemplary surface treatment techniquesfor deposition of feedstock material onto surface 51 include thermaldeposition techniques where feedstock is fed into a deposition device52. The feedstock can be converted to a spray 54 and sprayed ontosurface 51 to form a layer of material 56. Thermal deposition is notlimited to a specific technique, and can comprise, for example, a highpressure plasma system, a low pressure plasma system, a detonation gunsystem, a diamond coat system, a high velocity oxy-fuel (HVOF) system, atwin roll or single roll wire-arc system, or a high velocity wire-arcsystem. Examples of as-sprayed HVOF coatings of compositionFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ are shown in FIG. 7.

[0058] Prior to any subsequent treatment, as-sprayed layer 56 cancomprise a microstructure that includes at least some metallic glass.The amount of amorphous structure within layer 56 will depend upon thedeposition method, the deposition conditions, and the composition of thefeedstock material. As-sprayed, layer 56 can comprise a hardness ofgreater than about 9.2 GPa. Typically, layer 56 will comprise a hardnessof between about 9.2 GPa and about 15.0 GPa.

[0059] Hardness of an as-sprayed layer can be affected by porosity. Itcan be advantageous to produce a layer or coating comprising a lowporosity since increased porosity of a material can result in acorresponding decrease in hardness of the material. As shown in FIG. 8,layer 56 can have a porosity of as low as 0.06%. Typically, layer 56will comprise a porosity of less than or equal to about 5%(corresponding to a layer density of greater than or equal to about95%). FIG. 9 shows porosities of (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂coatings formed by three different coating deposition techniques. Theplasma coating shown in Panel A has a porosity of 0.9%, the HVOF coatingin Panel B has a porosity of 0.7%, and the wire-arc coating shown inPanel C has a porosity of 3.3%. Table 2 reports the determined hardnessfor each of the three layers shown in FIG. 9. As will be understood bythose skilled in the art, porosity of layer 56 can be increased ifdesired by incorporation of oxygen during the spray deposition of thelayer, or by spraying with non-optimized spray parameters. It issometimes desirable to have a higher porosity layer, for example toabsorb oil. TABLE 2 Properties of Coatings Produced by Various SprayTechniques PROPERTY HVOF Coating Plasma Coating Wire-arc CoatingPorosity (%) 0.7 0.9 3.3 Hardness as- 10.0 GPa 11.0 GPa 12.7 GPa sprayedHardness after 14.5 GPa 13.5 GPa 13.5 GPa 1 hr at 700° C.

[0060] X-ray diffraction studies performed on the free surface side of asingle as-sprayed, 330 micrometer thick layer show a lack of long rangeordered microstructure as shown in FIG. 10, thereby indicating anamorphous structure of the coating. As-sprayed layer 56 can comprisesome measurable amorphous structure, can comprise primarily amorphousstructure (greater than 50% of the microstructure), or can comprise upto about 100% amorphous structure.

[0061] Due to the lack of long range ordered microstructure in metallicglass, the presence of metallic glass allows layer 56 to be formed inthe absence of any interfacial layer (such as bond coat), betweencoating layer 56 and surface 51 as shown in FIG. 6. An interfacial layeris not required since there is little or no crystal structure mismatchbetween the material of surface 51 and coating layer 56 due to thepresence of amorphous microstructure within layer 56. Although FIG. 6shows an absence of an interfacial layer, it is to be understood thatthe invention encompasses embodiments wherein an interfacial layer isprovided (not shown).

[0062] Although FIG. 6 shows a single layer 56, it is to be understoodthat the present invention encompasses a coating comprising amulti-layer thickness (not shown). As-sprayed layer 56 can comprise amulti-layer thickness of from about 25 microns to about 6500 microns. Ifpowder feedstock is utilized, layer 56 can preferably comprise amulti-layer thickness of from about 250 microns to about 350 microns. Ifwire feedstock is utilized, layer 56 can preferably comprise amulti-layer thickness of from about 750 microns to about 1500 microns.

[0063] A coating comprising a multi-layer thickness can be formed by,for example, sequentially depositing individual layers according to themethods described above. X-ray diffraction scans of the free surfaceside (FIG. 11A) and the substrate surface side (after delamination, FIG.11B) of a 1650 micron thick, multilayer coating show that an amorphousstructure was maintained during a multilayer plasma-deposition process.FIG. 12 shows an x-ray scan indicating the amorphous structure of a{fraction (1/4)} inch thick multilayer coating formed by twin-roll wirearc spray deposition.

[0064] Differential thermal analysis (DTA) was performed to show theglass to crystalline transformation for an atomized powder feedstock, anHVOF coating and a plasma spray coating, of the compositionFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄. The DTA scans shown in FIG. 13, combined withdifferential scanning calorimetry (DSC) measurements, indicate that thepowder feedstock comprised 46% glass structure, the HVOF coatingcontained 41% glass structure, and the plasma coating contained 86%glass structure. The DSC trace shown in FIG. 14 was obtained from a{fraction (1/4)} inch thick wire-arc coating of the compositionFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄.

[0065] In addition to comprising a substantial hardness of at leastabout 9.2 GPa, as-sprayed layer 56 can comprise a substantial toughnesswhich is increased relative to a toughness of the cooled-alloy solidmass form of the corresponding composition (discussed above). Forexample, when a maximum density is achieved as-sprayed layer 56 cancomprise a tensile elongation up to about 60%.

[0066] Referring again to FIG. 2, once a metallic material has beenapplied to a surface in step (H), the metallic material can be furthertreated in step (I) to devitrify some or all of the metallic glasspresent in the metallic material to form crystalline havingnanocrystalline grain size. Devitrification step (I) can result in anincreased hardness of the devitrified layer relative to the as-sprayedlayer.

[0067] Devitrification step (I) can comprise heat treatment of theas-sprayed layer comprising heating to a temperature from above thecrystallization temperature of the particular alloy to less than themelting temperature of the alloy composition of the layer, and cancomprises heating from between 1 minute to about 1000 hours.Devitrification step (I) will typically comprise heating from about 550°C. to about 850° C. for between about 10 minutes and about 1 hour.

[0068] Heat treatment of metallic glass material enables a solid statephase change wherein the amorphous metallic glass can be converted toone or more crystalline solid phases. The solid state devitrification ofamorphous glass structure enables uniform nucleation to occur throughoutthe amorphous material to form nanocrystalline grains within the glass.The metallic matrix microstructure formed by devitrification cancomprise a steel matrix (iron with dissolved interstitials) or a complexmulti-phase matrix comprising several phases, one of which is ferrite.The nanocrystalline scale metal matrix composite grain structure canenable a combination of mechanical properties which are improvedcompared to the properties which would exist with larger grain sizes orwith the metallic glass. Such improved mechanical properties caninclude, for example, high strength and high hardness and for particularcompositions of the present invention can include a maintained or evenincreased toughness relative to materials comprising larger grain sizesor comprising metallic glass.

[0069] The resulting structure of devitrified material can comprisenanoscale grains comprising from about 50 to about 150 nanometer grainsize. Additionally, the devitrified material can comprise second phaseprecipitates at grain boundaries having a precipitate size of on theorder of 20 nanometers. FIG. 15, FIG. 16 and FIG. 8 show TEM micrographsof the microstructure comprised by heat treated materials formed bymethods of the present invention. Referring to FIG. 15, thenanocrystalline microstructure of a devitrified material comprising(Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂ is shown after treatment at varioustemperatures for one hour. FIG. 15 also shows a selected areadiffraction pattern for each of the three treatment conditions. FIG. 16shows the nanocrystalline microstructure and selected area diffractionpatterns of a devitrified material comprising(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ after treatment at varioustemperatures for one hour.

[0070]FIG. 17 shows a TEM micrograph of the nanocrystallinemicrostructure of a devitrified layer comprising Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄which was formed using HVOF deposition followed by heat treatment for 1hour at 750° C. The TEM indicates a nanoscale structure having grainsfrom about 75 nm to about 125 nm with 20 nm second phase precipitates atthe grain boundaries. The sample shown in FIG. 17 was used to obtain thex-ray diffraction data scan shown in FIG. 18, Panel A which was in turnrefined as shown in FIG. 18, Panel B to identify the nanocompositestructure summarized in Table 3. TABLE 3 Phase Information forDevitrified (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ Phase Crystal SystemSpace Group Lattice Parameters (Å) α-Fe Cubic Im3m a = 2.902 Fe₂BTetragonal I4/mcm a = 5.179, c = 4.299 Cr₂₃C₆ Cubic Fm3m a = 10.713

[0071] As shown in Table 4, a devitrified nanocomposite materialaccording to methods of the present invention can have a hardness thatis increased as much as 5.2 GPa relative to the corresponding glassmaterial (prior to devitrification). As Table 4 indicates, methods ofthe present invention can be utilized for production of hard glassmaterials or hard nanocomposite materials which have increased hardnessover the corresponding ingot form even for compositions that have ahardness of less than 9.2 GPa when produced in ingot form. TABLE 4Hardness of Alloys in Ingot, Glass, and Nanocomposite ConditionsHardness (GPA) Alloy Composition Ingot Glass Nanocomposite(Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂  4.6 10.3 15.3 (Fe_(0.8)Mo_(0.2))₈₃B₁₇  5.110.5 15.0 (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂ 10.8 11.0 16.2(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂ 12.3 11.3 15.2Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ 13.2 12.1 15.5

[0072] Various methods were utilized to measure properties ofdevitrified materials produced by methods of the present invention. Theability to adhere to an underlying material was tested by conventionaltesting methods including drop-impact test, bend test and particleimpact erosion test. The coatings were able to pass all three of thesetests. FIG. 19 illustrates the elastic and plastic ductility(resiliency) of a coating comprising Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄. A steelstrip which has been coated with approximately 200 micron thickness ofcoating material by HVOF deposition is shown in Panel A. Panel B andPanel C show the lack of chipping cracking or peeling away of thecoating from the base metal upon deformation of the coated strip.

[0073]FIG. 20, Panel A shows an approximately 200 micron thickFe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄ coating on a flat plate. As shown, the coatingdemonstrates high ductility and toughness since it is able to deformwith the base metal during repeated hammering on the coating side (PanelB) or repeated hammering on the substrate side (Panel C). Additionally,no observable cracking, chipping or pulling away of the coating wasdetected upon severe deformation of the plate (Panel D).

[0074] Tensile properties of coating produced by methods of the presentinvention were measured by forming metallic ribbons of the compositionto be tested. Both metallic glass ribbons (FIG. 21) and devitrifiedribbons (FIG. 22) were subjected to various strain rates at a number oftemperatures. The stress/strain curves for metallic glass show thatelongation as high as 60% is attainable (FIG. 21, Panel A). Thedevitrified ribbon can exhibit superplasticity, having a maximumelongation of up to about 180% (FIG. 22).

[0075] The methodology described herein can have application for anumber of uses including, but not limited to, such uses as protectivecoatings and hard-facing. In such applications, metallic coatingsproduced by methods of the present invention can be used on surfaces ofparts, devices, and machines to protect such surfaces from one or moreof corrosion, erosion, and wear. Such applications can utilize eitheras-sprayed coatings comprising metallic glasses or devitrified materialcomprising nanocomposite structure. Additionally, such applications canutilize coatings having some metallic glass structure and somenanocomposite structure. Such partially-glass/partially-nanocompositecoatings can be formed by, for example, sequentially forming individuallayers and heat treating only specific layers, or by sequentiallyforming one or more layers and only heat treating a portion of the oneor more layers.

[0076] Due to the hardness of as-sprayed metallic glass materials formedby methods of the present invention, coatings can utilize the as-sprayedmaterial without further devitrification. In other applications where anincreased hardness is desired, full devitrification can be performed andcan achieve up to 100% nanocomposite microstructure comprising extremehardness. The increase in hardness produced by methods of the presentinvention can be achieved without an accompanying loss of toughness, andcan even be accompanied by an increased toughness.

[0077] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method of producing a hard metallic material, comprising: providinga mixture of elements, the mixture comprising at least about 55 percentFe by weight, and at least one element selected from the groupconsisting of B, C, Si and P; forming the mixture into an alloy; andcooling the alloy at a rate of less than about 5000 K per second to forma metallic material having a hardness of greater than about 9.2 GPa. 2.The method of claim 1 wherein the metallic material is in ingot form. 3.The method of claim 1 wherein the mixture comprises at least onetransition metal selected from the group consisting of W, Mo, Cr and Mn.4. The method of claim 1 wherein the mixture comprises one or more of Aland Gd.
 5. The method of claim 1 wherein the mixture comprises at leasttwo of B, C and Si.
 6. The method of claim 1 wherein the mixturecomprises B, C and Si at an atomic ratio of B₁₇C₅Si₁.
 7. The method ofclaim 1 wherein the mixture comprises a composition selected from thegroup consisting of Fe₆₃B₁₇C₃Si₃, (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂,Fe₆₃B₁₇C₃Si₅, Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈, Fe₆₃,B₁₇C₅,(Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁, Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅,(Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂,Fe₆₃Cr₈Mo₂B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁,Fe₆₃Cr₈Mo₂B₁₇C₅Si₁,Al₄, (Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁,Gd₁, (Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 8. The method of claim 1 wherein thealloy comprises a melting temperature of less than or equal to about1550° C.
 9. The method of claim 1 wherein the mixture consistsessentially of fewer than 11 elements.
 10. The method of claim 1 whereinthe mixture consists essentially of fewer than 9 elements.
 11. Ametallic material comprising: at least 55% Fe;. at least one of B, Si, Pand C; a total element composition consisting essentially of fewer than11 elements; a melting temperature between about 1100° C. and about1250° C. and a hardness of greater than about 9.2 GPa.
 12. The metallicmaterial of claim 11 wherein the material is a cast material.
 13. Themetallic material of claim 11 wherein the material is in ingot form. 14.The metallic material of claim 11 wherein the total element compositionconsists of fewer than 11 elements.
 15. The metallic material of claim11 comprising B, Si and C.
 16. The metallic material of claim 11 whereinthe total elemental composition consists essentially of fewer than 9elements.
 17. The metallic material of claim 11 comprising a compositionselected from the group consisting of Fe₆₃B₁₇C₃Si₃,(Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅, Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈,Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁, Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅,(Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂,Fe₆₃Cr₈Mo₂B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 18. A method of forming a wire,comprising: providing a metal strip having a first composition;providing a powder comprising a second composition; and combining thefirst composition and the second composition by rolling the metal striptogether with the powder to form a wire comprising a third composition,the third composition containing at least 55 weight percent Fe and fromtwo to seven additional elements, the two to seven additional elementscomprising at least two element selected from the group consisting of C,Si and B.
 19. The method of claim 18 wherein the powder comprises ametallic glass.
 20. The method of claim 18 wherein the third compositioncomprises at least one transition elements selected from the groupconsisting of W, Mo, Cr and Mn.
 21. The method of claim 18 wherein thethird composition comprises C, Si and B.
 22. The method of claim 21wherein the C, Si and B are present in the third composition at anatomic ratio of B₁₇C₅Si₁.
 23. The method of claim 18 wherein the thirdcomposition comprises at least one member selected from the groupconsisting of Fe₆₃B₁₇C₃Si₃, (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅,Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈, Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁,Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅, (Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂, Fe₆₃Cr₈Mo₂B₁₇C₅,(Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 24. The method of claim 18 whereinthe wire comprises a diameter of from about 0.035 inches to about 0.188inches.
 25. A wire comprising a total composition consisting essentiallyof fewer than 11 elements, the fewer than 11 elements comprising Fe andat least two elements selected from the group consisting of C, Si and B,the Fe present in the total composition being at least about 55% of thetotal composition by weight.
 26. The wire of claim 25 furthercomprising: a metal sheath comprising a first sub-composition; and acore comprising a powder having a second sub-composition, wherein thefirst sub-composition a the second sub-composition are collectivelycomprised by the total composition of the wire.
 27. The wire of claim 26wherein the powder comprises a metallic glass.
 28. The wire of claim 25wherein the total composition comprises a member selected from the groupconsisting of Fe₆₃B₁₇C₃Si₃, (Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅,Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈, Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁,Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅, (Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂, Fe₆₃Cr₈Mo₂B₁₇C₅,(Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 29. A method of forming a hardenedsurface on a substrate, comprising: providing a solid mass comprising afirst hardness; processing the solid mass to form a powder; applying thepowder to a surface of a substrate to form a layer having a secondhardness, at least some of the layer comprising metallic glass; andconverting at least some of the metallic glass to a crystalline materialhaving a nanocrystalline grain size, the converting hardening the layerto form a hardened layer having a third hardness that is greater thanthe first hardness and greater than the second hardness.
 30. The methodof claim 29 wherein the solid mass comprises an ingot form.
 31. Themethod of claim 29 wherein the powder comprises at least some amorphousstructure.
 32. The method of claim 29 wherein the converting comprisesheating the layer to a temperature between about 600° C. and a meltingtemperature of the metallic glass.
 33. The method of claim 29 whereinthe solid mass comprises a first toughness, wherein the layer prior tothe converting comprises a second toughness, and wherein the hardenedlayer comprises a third toughness, the second toughness and the thirdtoughness each being equal to or greater than the first toughness. 34.The method of claim 29 wherein the solid mass comprises a composition offrom 3 to 11 elements, the composition comprising at least about 55percent iron by weight, and at least two of B, C and Si.
 35. The methodof claim 33 wherein the composition comprises fewer than nine elements.36. The method of claim 33 wherein the composition comprises at leastone transition metal.
 37. The method of claim 29 wherein the layer isformed on the surface of a substrate in an absence of an interfaciallayer.
 38. The method of claim 29 wherein the solid mass comprises acomposition selected from the group consisting of Fe₆₃Mo₂Si₁,Fe₆₃Cr₈Mo₂, Fe₆₃Mo₂Al₄, (Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂,(Fe_(0.8)Mo_(0.2))₈₃B₁₇, Fe₆₃B₁₇Si₁, Fe₆₃Cr₈Mo₂C₅, Fe₆₃Mo₂C₅, Fe₈₀Mo₂₀,Fe₆₃Cr₈Mo₂B₁₇, Fe₈₃B₁₇, Fe₆₃B₁₇Si₅, Fe₆₃B₁₇C₂, Fe₆₃B₁₇C₃Si₃,(Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅, Fe₆₃B₁₇, C₂W₂, Fe₆₃B₁₇C₈,Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁, Fe₆₃B₁₇C_(W) ₅,Fe₆₃B₁₇C₅Si₅, (Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂, Fe₆₃Cr₈Mo₂B₁₇C₅,(Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 39. The method of claim 29 whereinthe first hardness is at least about 9.2 GPa.
 40. The method of claim 29wherein the applying the powder to the surface comprises at least one ofplasma spray thermal deposition, diamond jet thermal deposition andhigh-velocity oxy-fuel thermal deposition.
 41. The method of claim 29further comprising: prior to the applying the powder to the surface,combining the powder with a metal strip to form a wire, the wire havinga final composition comprising at least 55% iron by weight and at leastone element selected from the group consisting of Si, C, P and B; andwherein the applying the powder to the surface comprises at least one oftwin-roll wire arc deposition, single-roll wire arc deposition andhigh-velocity wire arc deposition.
 42. A method of protecting a surface,comprising: providing a surface; and applying an initially-formed layerof a material on the surface, the material comprising at least 55% Fe byweight and fewer than 10 additional elements, the fewer than 10additional elements comprising at least two of B, C and Si, theinitially-formed layer comprising an initial hardness of at least about9.2 GPa, having a tensile elongation of from about 0.5% to about 60%.43. The method of claim 41 wherein the surface is a metallic surface.44. The method of claim 41 wherein the initially-formed layer comprisesan amorphous structure.
 45. The method of claim 41 further comprising:converting the initially-formed layer into a hardened layer comprisingan increased hardness, the increased hardness being greater than theinitial hardness.
 46. The method of claim 44 wherein the hardened layercomprisies a nanocomposite microstructure having a grain size of fromabout 75 nm to about 125 nm, and having second phase precipitates ofabout 20 nm at grain boundaries.
 47. A hardfacing material comprising:an Fe-based alloy comprising at least one of C, B and Si and comprisingfewer than eleven elements; and at least some devitrified structurecomprising a nanocrystalline grain size, the hardfacing material havinga hardness of at least about 9.2 GPa, having a tensile elongation offrom about 5% to about 180%.
 48. A hardfacing material comprising anFe-based alloy comprising at least one of C, B and Si and comprisingfewer than eleven elements, the hardfacing material having at least someamorphous glass structure, having a hardness of at least about leastabout 9.2 GPa, having a tensile elongation of from about 0.5% to about60%.
 49. The hardfacing material of claim 47 wherein the Fe-based alloycomprises C, B and Si present in the alloy at an atomic ratio ofB₁₇C₅Si₁.
 50. The hardfacing material of claim 47 wherein the Fe-basedalloy comprises a composition selected from the group consisting ofFe₆₃Mo₂Si₁, Fe₆₃Cr₈Mo₂, Fe₆₃Mo₂Al₄, (Fe_(0.8)Cr_(0.2))₈₁B₁₇W₂,(Fe_(0.8)Mo_(0.2))₈₃B₁₇, Fe₆₃B₁₇Si₁, Fe₆₃Cr₈Mo₂C₅, Fe₆₃Mo₂C₅, Fe₈₀Mo₂₀,Fe₆₃Cr₈Mo₂B₁₇, Fe₈₃B₁₇, Fe₆₃B₁₇Si₅, Fe₆₃B₁₇C₂, Fe₆₃B₁₇C₃Si₃,(Fe_(0.8)Cr_(0.2))₇₉B₁₇W₂C₂, Fe₆₃B₁₇C₃Si₅, Fe₆₃B₁₇C₂W₂, Fe₆₃B₁₇C₈,Fe₆₃B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₈Mo₂W₂B₁₂C₅Si₁, Fe₆₃B₁₇C₅W₅, Fe₆₃B₁₇C₅Si₅,(Fe_(0.8)Cr_(0.2))₇₆Mo₂W₂B₁₄C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₆C₄Si₁Mn₂,Fe₆₃Cr₈Mo₂B₁₇C₅, (Fe_(0.8)Cr_(0.2))₇₅Mo₂B₁₇C₅Si₁, Fe₆₃Cr₈Mo₂B₁₇C₅Si₁Al₄,(Fe_(0.8)Cr_(0.2))₇₅W₂B₁₇C₅Si₁, Fe₆₃B₁₇C₅Si₁,(Fe_(0.8)Cr_(0.2))₇₃Mo₂W₂B₁₇C₅Si₁, (Fe_(0.8)Cr_(0.2))₇₂Mo₂W₂B₁₇C₅Si₁Gd₁,(Fe_(0.8)Cr_(0.2))₇₁Mo₂W₂B₁₇C₅Si₁Gd₂, and(Fe_(0.8)Cr_(0.2))₇₄Mo₂W₂B₁₇C₄Si₁.
 51. The hardfacing material of claim47 comprising a porosity of less than or equal to about 5%.
 52. Thehardfacing material of claim 47 comprising a porosity of less than orequal to about 1%.